World championship leader Lewis Hamilton put Mercedes on pole position for the Hungarian Grand Prix but it was a tough day for Australia's Daniel Ricciardo, who failed to make the top 10 after a qualifying session with thunder, lightning and plumes of spray.
Hamilton's teammate Valtteri Bottas will also be on the front row of the starting grid for Sunday's race, when conditions are expected to brighten up, with Ferrari's Kimi Raikkonen and Sebastian Vettel behind.
But Red Bull's Ricciardo was the biggest victim to fall foul to the changeable conditions on Saturday.
The Aussie failed to get in a good enough lap at the start of Q2, and as the rain intensified, he was unable to haul his car into the top-10 shootout and qualified only 12th.
Briton Hamilton now has 77 career poles, and five this season, but Saturday's went against the odds with the opportunity emerging as the heavens opened.
"It's great for the team to have a one-two. We couldn't have expected this," said the 33-year-old, who leads Vettel by 17 points after 11 races in the battle of four times world champions.
"Ferrari have been quickest all weekend and we were doing our best to catch up, but then the heavens opened and it was fair game.
"It's so tricky out there, at the beginning it was dry and then it got wetter so it was hard to say how much grip we had."
Vettel's Ferrari had been fastest in Friday and Saturday practice, with track record times.
Ricciardo's Dutch Red Bull teammate Max Verstappen qualified only seventh, with Renault's Carlos Sainz and Toro Rosso's Pierre Gasly fifth and sixth respectively.
McLaren's Fernando Alonso explained how wet the track had become when asked by his race engineer if he should stick to intermediate tyres or change to the full wet rubber.
"We should go to the garage," he said. "Put on whatever you like. The last sector is impossible. Even if you put on a rocket ship we will [fail to improve on] 11th."
